Magnetostriction of Ni2Mn1−xCrxGa Heusler Alloys

Sakon, Takuo; Fujimoto, Naoki; Kanomata, T.; Adachi, Yasuhiro

doi:10.3390/met7100410

Cited by 26 publications

(19 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The value of T C for x = 0.00 (Ni 2 MnGa) has been found to be 375 K, using the same approach [16]. For 0≤x≤0.25, the premartensitic phase was observed before the martensitic transition occurred [27,28,29]. Singh et al performed X-ray measurements and demonstrated that the crystal structure of Ni 2 MnGa in the premartensitic phase was a 3M-like incommensurate structure [30].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

The Characteristic Properties of Magnetostriction and Magneto-Volume Effects of Ni2MnGa-Type Ferromagnetic Heusler Alloys

et al. 2019

View full text Add to dashboard Cite

In this article, we review the magnetostriction and magneto-volume effects of Ni2MnGa-type ferromagnetic Heusler alloys at the martensitic, premartensitic, and austenitic phases. The correlations of forced magnetostriction (ΔV/V) and magnetization (M), using the self-consistent renormalization (SCR) spin fluctuation theory of an itinerant electron ferromagnet proposed by Takahashi, are evaluated for the ferromagnetic Heusler alloys. The magneto-volume effect occurs due to the interaction between the magnetism and volume change of the magnetic crystals. The magnetic field-induced strain (referred to as forced magnetostriction) and the magnetization are measured, and the correlation of magnetostriction and magnetization is evaluated. The forced volume magnetostriction ΔV/V at the Curie temperature, TC is proportional to M4, and the plots cross the origin point; that is, (M4, ΔV/V) = (0, 0). This consequence is in good agreement with the spin fluctuation theory of Takahashi. An experimental study is carried out and the results of the measurement agree with the theory. The value of forced magnetostriction is proportional to the valence electron concentration per atom (e/a). Therefore, the forced magnetostriction reflects the electronic states of the ferromagnetic alloys. The magnetostriction near the premartensitic transition temperature (TP) induces lattice softening; however, lattice softening is negligible at TC. The forced magnetostriction at TC occurs due to spin fluctuations of the itinerant electrons. In the martensitic and premartensitic phases, softening of the lattice occurs due to the shallow hollow (potential barrier) of the total energy difference between the L21 cubic and modulated 10M or 14M structures. As a result, magnetostriction is increased by the magnetic field.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The reaction products were encapsulated in evacuated silica tubes and heated at 1073 K for 3 days and 773 K for 2 more days, then quenched in water. A detailed explanation of the experimental procedure has been given in a previous studies [16,27].…”

Section: Methodsmentioning

confidence: 99%

The Characteristic Properties of Magnetostriction and Magneto-Volume Effects of Ni2MnGa-Type Ferromagnetic Heusler Alloys

et al. 2019

View full text Add to dashboard Cite

show abstract

“…This first order magnetostructural transition (FOMST) involves significant changes in the thermal, magnetic, elastic and transport properties. Apart from the MCE, they are also known to show giant magnetoresistance (MR) [4][5][6][7], magneto-thermal conductivity [8], magnetostriction [9,10], etc. Most of these multifunctionalities are connected with the change in structural and magnetic properties across the FOMST.…”

Section: Introductionmentioning

confidence: 99%

Measurement independent magnetocaloric effect in Mn-rich Mn-Fe-Ni-Sn(Sb/In) Heusler alloys

Ghosh

Rawat

Bhattacharyya

et al. 2019

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

We report a systematic study on the magneto-structural transition in Mn-rich Fe-doped Mn-Fe-Ni-Sn(Sb/In) Heusler alloys by keeping the total valence electron concentration (e/a ratio) fixed. The martensitic transition (MT) temperature is found to shift by following a proportional relationship with the e/a ratio of the magnetic elements alone. The magnetic entropy change (ΔS M ) across MT for a selected sample (Mn 49 FeNi 40 Sn 9 In) has been estimated from three different measurement methods (isofield magnetization (M) vs temperature (T), isothermal M vs field (H) and heat capacity (HC) vs T). We observed that though the peak value of ΔS M changes with the measurement methods, the broadened shape of the ΔS M -T curves and the corresponding cooling power (~140 Jkg -1 ) remains invariant. The equivalent adiabatic temperature change (ΔT) ~ -2.6 K has been obtained from indirect measurements of ΔT. Moreover, an exchange bias field ~ 783 Oe at 5 K and a magnetoresistance of -30% are also obtained in one of these materials.

show abstract

“…Ferromagnetic alloys, which exhibit the shape memory effect (Heusler alloys), belong to the class of functional (smart) materials [1][2][3][4][5][6][7][8][9][10]. The configuration of structures made of such materials can significantly change under the action of external thermal, magnetic, or electric fields.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of the Phase Transition Control in a Cylindrical Sample Made of Ferromagnetic Shape Memory Alloy

Rogovoy

Stolbova

2019

Computation

View full text Add to dashboard Cite

The paper considers ferromagnetic alloys, which exhibit the shape memory effect during phase transition from the high-temperature cubic phase (austenite) to the low-temperature tetragonal phase (martensite) in the ferromagnetic state. In these alloys, significant macroscopic strains are generated during the direct temperature phase transition from the austenitic to the martensitic state, provided that the process proceeds under the action of the applied mechanical stresses. The critical phase transition temperatures in such alloys depend not only on the stress fields, but also on the magnetic field. By changing the magnetic field, it is possible to control the process of phase transition. In this work, within the framework of the finite deformation theory, we develop a model that allows us to describe the process of the control of the direct (austenite-martensite) and reverse (martensite-austenite) phase transitions in ferromagnetic shape memory polycrystalline materials under the action of external force, thermal, and magnetic fields with the aid of the magnetic field. In view of the fact that the magnetic field affects the material deformation, which, in turn, changes the magnetic field, we formulated and solved a coupled boundary value problem. As an example, we considered the problem of a shift of the outer surface of a long hollow cylinder made of ferromagnetic alloy. The numerical implementation of the problem was based on the finite element method using the step-by-step loading procedure. Complete recovery of the strains accumulated during the direct phase transition and reverting of the axially-displaced outer surface of the cylinder to its original position occurred both on heating of the sample to the temperatures of the reverse phase transition and at a constant temperature, when the magnetic field previously applied in the martensitic state was removed.

show abstract

Magnetostriction of Ni2Mn1−xCrxGa Heusler Alloys

Cited by 26 publications

References 46 publications

The Characteristic Properties of Magnetostriction and Magneto-Volume Effects of Ni2MnGa-Type Ferromagnetic Heusler Alloys

The Characteristic Properties of Magnetostriction and Magneto-Volume Effects of Ni2MnGa-Type Ferromagnetic Heusler Alloys

Measurement independent magnetocaloric effect in Mn-rich Mn-Fe-Ni-Sn(Sb/In) Heusler alloys

Numerical Simulation of the Phase Transition Control in a Cylindrical Sample Made of Ferromagnetic Shape Memory Alloy

Contact Info

Product

Resources

About